Studies will be conducted to identify and quantitate di- and monophenolic amines formed from C14 tyrosine in organophosphorus (O-P) insecticide intoxicated and control insects. Tyrosinase in hemolymph from O-P intoxicated and control insects will be characterized further and its activity will be correlated with levels of pharmacologically active substances by bioassay techniques. Studies will be continued to measure levels of free and bound acetylcholine in nervous tissue of O-P intoxicated and control animals.